By this time next year, if all goes according to plan, the world's first human head transplant will have taken place, Italian surgeon Sergio Canavero has revealed.

In early 2015, Canavero made headlines around the world when he announced that he would perform the ground-breaking surgery within two years. Now, he has revealed in an interview with German magazine OOOM that it's going to take place within 10 months, in China.

The patient will not be previous transplant volunteer Valery Spiridonov, who has a form of spinal muscular atrophy called Werdnig-Hoffmann Disease.

Canavero claims to have successfully performed the procedure on a monkey. But other scientists have expressed ethical concerns. New York University bioethicist Arthur Caplan said Canavero was "out of his mind," noting that even if the procedure can be performed successfully, we have no idea what effect the chemistry of a new body would have on the transplanted head and brain.

Canavero seems confident.

"At the present I can only disclose that there has been massive progress in medical experiments, which would have seemed impossible even as recently as a few months ago," he said. "The milestones that have been reached will undoubtedly revolutionise medicine. "

He is also already preparing for his next experimental surgery -- transplanting not the entire head, but just the brain. He believes he can accomplish this in three years.

"A brain transplant has many advantages: first, there is barely any immune reaction, which means the problem of rejection does not exist. The brain is, in a manner of speaking, a neutral organ. If you transplant a head with vessels, nerves, tendons and muscles, rejection can pose a massive problem. This is not the case with the brain," he explained.

"What may be problematic, however, is that no aspect of your original external body remains the same. Your head is no longer there; your brain is transplanted into an entirely different skull."